Have we really acquired substantial new evidence on the relative effectiveness of N95 masks in the past two years? The most recent survey I read was: Physical

Have we really acquired substantial new evidence on the relative effectiveness of N95 masks in the past two years? The most recent survey I read was: Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 1 - Face masks, eye protection and person distancing: systematic review and meta-analysis (https://www.medrxiv.org/content/10.1101/2020.03.30.20047217v2 https://www.medrxiv.org/content/10.1101/2020.03.30.20047217v...) Quote: We found insufficient evidence for a difference between surgical masks and N95 respirators... The most thorough review I've read: Effectiveness of N95 respirators versus surgical masks in protecting health care workers from acute respiratory infection: a systematic review and meta-analysis (https://www.cmaj.ca/content/188/8/567 https://www.cmaj.ca/content/188/8/567) Conclusion: Although N95 respirators appeared to have a protective advantage over surgical masks in laboratory settings, our meta-analysis showed that there were insufficient data to determine definitively whether N95 respirators are superior to surgical masks in protecting health care workers against transmissible acute respiratory infections in clinical settings. Additional, large RCTs are needed to detect a potentially clinically important difference owing to small event rates. Initial guidelines on preventing acute respiratory infection relied on surrogate exposure data and data extrapolated from the protection of health care workers against tuberculosis because clinical evidence did not exist at that time. Randomized controlled trials conducted in clinical settings represent the most valid information to evaluate the effectiveness of N95 respirators. They are more relevant to real clinical situations and report actual outcomes in health care workers, and therefore they are the best evidence on effectiveness to inform policy-making.